The present invention relates to a vibration damping device, in particular for damping powertrain vibrations in an electric hand machine tool. The present invention also relates to a transmission, in particular for an electric hand machine tool, equipped with such a vibration damping device.
A transmission of an electric hand machine tool contains gears with a helical or threaded gearing, which are usually sintered for cost reasons. Cut gears, whose production costs are high, are only used for high-quality units that require a high degree of running smoothness. In comparison to cut gears, sintered gears have higher manufacture-induced tolerances. In a transmission, this can lead to additional oscillations and vibrations in the power train.
Prior inventions have already proposed inserting spring elastic damping elements, in particular made of rubber or a rubber-like material, between the drive gear and the output shaft to reduce power train vibrations. The damping elements, which act tangentially between the drive gear and the output shaft, compensate for vibrations. They also reduce the powerful starting forces exerted on the gearing, which occur due to the inertia of masses when the drive motor is switched on or reduce the load peaks occurring in the gearing during operation.